What was found
FLT 4149 - ON APPROACH AFTER LANDING GEAR WAS SELECTED 'DOWN', CREW REPORTED 'NO' DOWN AND LOCKED INDICATION FOR THE LEFT MAIN GEAR. CREW CONDUCTED A TOWER FLY-BY TO CONFIRM A GEAR DOWN CONDITION. ATC DECLARED AN EMERGENCY, EQUIPMENT ROLLED. AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. OUT STATION MAINTENANCE REPLACED BULBS IN THE LANDING GEAR POSITION INDICATOR IAW MM 32-00-00. GROUND CHECK 'GOOD'. AIRCRAFT RETURNED TO SERVICE. (X)